The present invention relates to an attaching arrangement and, more particularly, to a spring element for attaching wheel covers to rims of a vehicle whereby the fastening takes place by snap-in action and the spring elements are secured at the wheel cover.
It is known in the prior art to secure wheel covers which cover a wheel rim, on the wheel rim by snap-in action. Thus, it is known, for example, from the German Gebrauchmuster 1,975,618 that retaining springs detachably secured at the wheel cover are formed by sheet metal strips which can be suspended in the axial direction in the rear area of the wheel cover and take over the retention of the wheel cover by means of a bulge-like part forming the rear part of the spring. The sheet metal strip is made with a longer and a shorter leg, whereby the longer upwardly pointing leg cooperates with the outer edge of the wheel cover bent in the rearward direction and the shorter, downwardly bent leg includes a tab or lug which is also suspended at the wheel cover in a bend.
A disadvantage of the aforementioned prior art construction resides in the fact that manufacturing the strips for forming the springs is relatively expensive from a material point of view since, in a circumferential direction, the springs must extend over a certain width in order to be able to ensure an adequate spring constant.
A further disadvantage of the aforementioned prior art construction resides in the fact that the springs cannot be used for attaching wheel covers to rims having a considerable axial depth because the lever distance which occurs thereby between the attachment point of the clip or tongue-like member and the seat of the bulge of the spring establishing the connection becomes so large that the spring force becomes diminished to a point where it is ineffective in its ability to reliably secure the wheel cover.
Yet another disadvantage of the aforementioned prior art sheet steel spring elements resides in the fact that, with such elements, it is no longer possible to influence the spring travel and therewith the hardness or stiffness of the spring system once the sheet metal spring member has been made. Consequently, if different spring constants are desired, different strips of sheet steel with appropriate desired spring constants must be produced.
It has also been found as a disadvantage with this prior art construction that the retaining springs must exert relatively large forces with respect to the wheel cover and/or the wheel rim for reasons of manufacturing tolerances and of different coefficients of thermal expansions of the parts used for the manufacture, if a secure retention of the wheel cover at the rim is to be assured in every case.
Fastening systems for wheel covers are also known (German Offenlegungsschrift 2,622,908) in which a radially springy wire ring is provided for fastening the wheel cover. However, the relatively large manufacturing expenditure for the wheel cover and wire ring is disadvantageous with such types of construction. Added thereto is the fact that a sufficiently large structural volume in the radial direction must be available to such a wire ring in order to be able to fulfill its function. Such wire rings cannot be used, therefore, in particular in those cases in which the structural volume necessary therefor is not available by reason of constructive features, for example, relatively large pressed-in depths of the wheel dish.